An engineering application process for efficient iron and phosphorus extraction from phosphorus-containing roasted ore

Abstract

The present invention provides a beneficiation process for roasted high-phosphorus oolitic iron ore, comprising the following steps: firstly, the roasted ore after roasting the high-phosphorus oolitic iron ore is ground to obtain ground ore; then, the ground ore obtained in the above step is subjected to weak magnetic separation, and then demagnetized to obtain demagnetized ore; finally, the demagnetized ore obtained in the above step is subjected to stirring leaching and filter pressing to obtain leached ore, and then, after slag removal and washing, iron concentrate is obtained. The process is particularly suitable for the engineering application production of leaching and dephosphorization of roasted high-phosphorus oolitic iron ore that is difficult to handle. The test runs continuously for 72 hours without interruption, and the continuously produced iron concentrate product stably reaches TFe 64% or more, and the key impurity phosphorus content P <0.2%.

Description

Technical Field

[0001] The invention belongs to the technical field of high-phosphorus oolitic iron ore roasting ore beneficiation and hydrometallurgy, and relates to a beneficiation process of high-phosphorus oolitic iron ore roasting ore, and in particular to an engineering application process for efficiently increasing iron and reducing phosphorus in phosphorus-containing roasting ore. Background Art

[0002] High-phosphorus oolitic iron ore is an important type of iron ore, which is widely distributed on the surface of the earth's crust. Its concentrated distribution areas include Superior region in North America, Minnesota region, Northern Europe, Australia, Saudi Arabia, etc. Although the domestic high-phosphorus iron ore reserves are high, the truly usable high-phosphorus iron ore resources are not abundant.

[0003] High-phosphorus oolitic iron ore generally contains metal minerals such as magnetite, hematite, limonite, siderite, and some non-metallic minerals such as quartz, clay minerals, and collophanite. The ore structure is mainly oolite, concentric ring-shaped, and impregnated. Iron ore and gangue minerals such as quartz, collophanite, chlorite, etc. are complex and closely related, often forming concentric rings with gangue minerals as the core. And the embedded particle size is generally around 10μm, which is very fine and usually has a high content of harmful impurities, such as phosphorus and aluminum, and a part of it is in the form of colloids, which are interdependent with oolites and difficult to separate, so it is difficult to reduce harmful impurities. The occurrence state of phosphorus is collophanite and apatite. Phosphorus is closely associated with iron, which often causes the phosphorus content in iron concentrate to exceed the standard. Because the gangue minerals and iron minerals are extremely fine and evenly distributed, it is difficult to obtain high iron concentrate products from this type of mineral, and it is known as the most difficult type of iron ore to be separated. With the development of steel product varieties, in the future metallurgical industry, the standards for smelting raw materials will be improved. Phosphorus, as a harmful substance in most steel materials, has strict restrictions. It is increasingly urgent to study iron-enhancing and phosphorus-reducing technology and comprehensively utilize high-phosphorus oolitic iron ore.

[0004] Based on the previous experimental research and production practice of oolitic hematite in various regions of the world, the reasons for the difficulty in selecting high-phosphorus oolitic iron ore are summarized as follows: 1) To dissociate the iron mineral monomer, the oolitic core or ring zone of the oolitic hematite with extremely fine particle size must be dissociated, which is a major challenge for current grinding, that is, grinding it to less than 30μm, or even finer; 2) Oolitic hematite deposits are sedimentary, usually accompanied by a lot of clay with low hardness, and these clays are When it is crushed, a large amount of ore mud will be produced, and these ore muds usually have a high iron grade, which will have a serious impact on the subsequent separation work; (3) The complex structure itself is also a major feature, and there are many types of oolitic hematite, some with limonite or hematite as oolite, and some with quartz or chlorite as oolite; 4) It usually contains high levels of harmful impurities, such as phosphorus and aluminum, and some are in the form of colloids, which are associated with oolites and are difficult to separate, making it difficult to reduce harmful impurities. Due to the complex nature and structure of the ore, it is difficult to use traditional methods to separate the ore. The development and application of new separation methods is the research direction.

[0005] Sinosteel Equipment, in cooperation with a number of domestic universities and research institutes, has actively developed high-phosphorus oolitic iron ore through nearly a decade of active research and development, and has made breakthroughs in key technologies in the development and utilization of the mine. Among them, the suspended magnetization roasting + leaching technology has made breakthrough progress. The laboratory research results are very good, but the following problems have been found in the engineering application of dephosphorization of roasted ore: 1) There are sedimentation tanks and stirring problems during the agitation and leaching of iron concentrate for dephosphorization; 2) The selected chemical leaching agent sulfuric acid is more friendly than hydrochloric acid, nitric acid or mixed acids, but in areas where chemical companies are underdeveloped abroad, the price of sulfuric acid is high, resulting in high costs; 3) After chemical dephosphorization of iron concentrate, there are a lot of flocculent sediments, which seriously affect the grade of iron concentrate.

[0006] Therefore, how to find a more suitable way to solve the above-mentioned problems existing in the engineering application of high-phosphorus oolitic iron ore has become one of the urgent problems to be solved by many front-line researchers in the industry. Summary of the invention

[0007] In view of this, the technical problem to be solved by the present invention is to provide a beneficiation process for high-phosphorus oolitic iron ore roasting, in particular, an engineering application process for efficient iron and phosphorus reduction in phosphorus-containing roasting. The beneficiation and smelting combined engineering and expanded production process provided by the present invention realizes the continuous leaching and stable dephosphorization of high-phosphorus oolitic iron ore roasting, and obtains high-quality iron concentrate products; and the process is simple, the conditions are mild, and the controllability is good, which is more suitable for the promotion and application of large-scale industrial production.

[0008] The present invention provides a beneficiation process for roasted high-phosphorus oolitic iron ore, comprising the following steps:

[0009] 1) grinding the roasted ore after roasting the high-phosphorus oolitic iron ore to obtain ground ore;

[0010] 2) subjecting the ground ore obtained in the above step to weak magnetic separation and then demagnetization to obtain demagnetized ore;

[0011] 3) The demagnetized ore obtained in the above steps is subjected to stirring leaching and filter pressing to obtain leached ore, and then slag removal and washing to obtain iron ore concentrate.

[0012] Preferably, the roasted ore comprises, by element mass content, TFe: 55.00% to 63.00%, P: 0.50% to 1.50%, S: 0.02% to 0.20%, CaO: 0.50% to 2.50%, MgO: 0.10% to 1.00%, SiO2: 4% to 8% and Al2O3: 4% to 8%.

[0013] Preferably, the calcination method includes suspended magnetization calcination;

[0014] The particle size of the ore grinding is less than 325 mesh, and the mass of the particles accounts for 65% to 75%.

[0015] Preferably, the weak magnetic separation is specifically wet weak magnetic separation;

[0016] The magnetic field strength of the weak magnetic separation is 600-1500 Gs.

[0017] Preferably, the demagnetization excitation current is 2.5 to 3.5 A;

[0018] The stirring leaching method is continuous stirring leaching, including slurry preparation, leaching and buffering steps.

[0019] Preferably, the stirring leaching process comprises the following steps:

[0020] The demagnetized ore slurry after slurry adjustment is sent to the slurry preparation device, and concentrated sulfuric acid is added for stirring and leaching, and then overflows to the leaching reaction device for further stirring and leaching, and then overflows to the buffer device.

[0021] Preferably, the liquid-to-solid ratio of the slurry after slurry adjustment is (2-8):1;

[0022] The ratio of the concentrated sulfuric acid to the ore pulp is (20-50) g:1L.

[0023] Preferably, during the stirring leaching process, the pH value is controlled to be 0.4 to 1.0;

[0024] The stirring speed of the stirring leaching is 200 to 500 rpm;

[0025] The residence time of the slurry in the batching device is 20 to 60 minutes.

[0026] Preferably, the stirring speed of the continued stirring and leaching is 200 to 500 rpm;

[0027] The residence time of the slurry in the reaction device is 20 to 60 minutes;

[0028] The slag removal and cleaning method includes using a device with magnetic force to perform magnetic washing and / or elutriation.

[0029] Preferably, the mineral processing process further includes an acid water circulation process;

[0030] The acid water circulation process comprises one or more of the following steps: returning the water generated in the weak magnetic separation process to the weak magnetic separation process for recycling;

[0031] The acid leaching liquid obtained after the filter press is returned to the slurry preparation process in the stirring leaching step for recycling;

[0032] The acidic washing water generated during the slag removal and cleaning is neutralized and returned to the slag removal and cleaning process for recycling.

[0033] The invention provides a beneficiation process for roasted high-phosphorus oolitic iron ore, comprising the following steps: firstly, grinding the roasted ore after roasting the high-phosphorus oolitic iron ore to obtain ground ore; then subjecting the ground ore obtained in the above step to weak magnetic separation and demagnetization to obtain demagnetized ore; finally, subjecting the demagnetized ore obtained in the above step to stirring leaching and filter pressing to obtain leached ore, and then subjecting the leached ore to slag removal and cleaning to obtain iron concentrate. Compared with the prior art, the ore dressing process creatively designed by the present invention is a new process for the iron-raising and phosphorus-reducing smelting of high-phosphorus oolitic iron ore roasting ore, which adopts a new process of grinding-magnetic separation-demagnetization-stirring leaching dephosphorization-slag removal. Stirring leaching uses sulfuric acid leaching dephosphorization to reduce the corrosion of equipment and reduce the amount of sulfuric acid used; the newly added demagnetization link can effectively reduce the magnetic agglomeration of iron concentrate, reduce the iron concentrate sedimentation phenomenon and the blockage of the slurry transportation pipeline during stirring leaching; weak magnetic separation washing or electromagnetic washing process can further improve the quality of the final product and achieve the purpose of iron-raising and phosphorus-reducing. The process is particularly suitable for the engineering application production of leaching and dephosphorization of difficult-to-handle high-phosphorus oolitic iron ore roasting ore. The present invention has the characteristics of reasonable process structure, simple and easy operation, low energy consumption, low acid consumption, good iron-raising and phosphorus-reducing effect, and environmental friendliness.

[0034] The new combined process for high-phosphorus oolitic iron ore roasting and phosphorus reduction beneficiation provided by the present invention can adapt to the leaching and dephosphorization of roasted ore, which is an artificial magnetite with strong magnetism. The designed grinding-magnetic separation-demagnetization-stirring leaching and dephosphorization-filter pressing-magnetic washing / elution and slag removal process can stabilize dephosphorization, enhance operating efficiency, significantly improve the quality of iron concentrate products, and improve engineering application effects; at the same time, it reduces the grinding fineness, reduces the consumption of leaching agent sulfuric acid, reduces the use of new water, etc., saves costs and increases efficiency, and greatly improves economic and environmental benefits. The present invention solves the engineering application problem of high-phosphorus oolitic iron ore roasting and iron reduction, opens the last barrier for the development and utilization of such ores, and lays the foundation for the large-scale industrial development and utilization of high-phosphorus oolitic iron ore.

[0035] The new combined beneficiation and smelting process provided by the present invention effectively solves the problems that the iron concentrate grinding particle size is too fine, the iron concentrate is easy to be stirred in the sedimentation tank during stirring and leaching, the dephosphorization effect of the product is unstable, and the iron grade of the final product is not high during the engineering application process. The invention is characterized by reducing grinding and low energy consumption; stirring and leaching adopts continuous leaching and stable dephosphorization; the acid leaching liquid is returned for leaching to achieve the purpose of acid recycling, etc., which can reduce the sulfuric acid cost by 30%, the product is stable TFe>64%, P<0.2%, and the content of other silicon and aluminum impurities does not exceed the standard; the used water is also comprehensively utilized, and the whole process is energy-saving, environmentally friendly, and very environmentally friendly.

[0036] The operation results show that the process is particularly suitable for the engineering application production of leaching and dephosphorization of difficult-to-treat high-phosphorus oolitic iron ore roasting. The test ran continuously for 72 hours without interruption. The continuously produced iron concentrate product stably reached a TFe of more than 64%, and the key impurity phosphorus content P<0.2%. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The present invention provides a simplified schematic diagram of the process flow of a new combined process for calcining high-phosphorus oolitic iron ore to increase iron content and reduce phosphorus. DETAILED DESCRIPTION

[0038] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the invention.

[0039] All raw materials of the present invention have no particular limitation on their sources and can be prepared by conventional methods known to those skilled in the art.

[0040] The present invention provides a beneficiation process for roasted high-phosphorus oolitic iron ore, comprising the following steps:

[0041] 1) grinding the roasted ore after roasting the high-phosphorus oolitic iron ore to obtain ground ore;

[0042] 2) subjecting the ground ore obtained in the above step to weak magnetic separation and then demagnetization to obtain demagnetized ore;

[0043] 3) The demagnetized ore obtained in the above steps is subjected to stirring leaching and filter pressing to obtain leached ore, and then slag removal and washing to obtain iron ore concentrate.

[0044] The invention firstly grinds the roasted ore after roasting the high-phosphorus oolitic iron ore to obtain a ground ore product.

[0045] In the present invention, the roasted ore preferably comprises, by element mass content, TFe: 55.00% to 63.00%, P: 0.50% to 1.50%, S: 0.02% to 0.20%, CaO: 0.50% to 2.50%, MgO: 0.10% to 1.00%, SiO2: 4% to 8% and Al2O3: 4% to 8%, more preferably TFe: 56.00% to 62.00%, P: 0.70% to 1.30%, S: 0.05% to 0.17%, CaO: 0.90% ~ 2.0%, MgO: 0.30% ~ 0.80%, SiO2: 4.5% ~ 7.5% and Al2O3: 4.5% ~ 7.5%, more preferably TFe: 57.00% ~ 61.00%, P: 0.90% ~ 1.10%, S: 0.08% ~ 0.14%, CaO: 1.40% ~ 1.5%, MgO: 0.50% ~ 0.60%, SiO2: 5% ~ 7% and Al2O3: 5% ~ 7%.

[0046] In the present invention, the calcination method preferably includes suspended magnetization calcination.

[0047] In the present invention, the particle size of the grinding is preferably 65% ​​to 75% by mass of particles smaller than 325 mesh, more preferably 66% to 73%, and more preferably 68% to 70%. Specifically, the mass of particles smaller than 325 mesh accounts for 65% to 75%, that is, the mass content of particles under the 325 mesh sieve is 65% to 75%.

[0048] In the present invention, the ground ore obtained in the above steps is subjected to weak magnetic separation and then demagnetized to obtain demagnetized ore.

[0049] In the present invention, the weak magnetic separation is preferably wet weak magnetic separation.

[0050] In the present invention, the magnetic field strength of the weak magnetic separation is preferably 600-1500 Gs, more preferably 800-1300 Gs, and more preferably 1000-1100 Gs.

[0051] In the present invention, the demagnetization excitation current is preferably 2.5 to 3.5A, more preferably 2.7 to 3.3A, and more preferably 2.9 to 3.1A.

[0052] In the present invention, the demagnetized ore obtained in the above steps is finally subjected to stirring leaching and pressure filtration to obtain leached ore, and then subjected to slag removal and washing to obtain iron concentrate.

[0053] In the present invention, the stirring leaching method is preferably continuous stirring leaching, including slurry preparation, leaching and buffering steps.

[0054] In the present invention, the stirring leaching process preferably comprises the following steps:

[0055] The demagnetized ore slurry after slurry adjustment is sent to the slurry preparation device, and concentrated sulfuric acid is added for stirring and leaching, and then overflows to the leaching reaction device for further stirring and leaching, and then overflows to the buffer device.

[0056] In the present invention, the liquid-to-solid ratio of the slurry after slurry adjustment is preferably (2-8):1, more preferably (2.5-7):1, and more preferably (3-6):1.

[0057] In the present invention, the ratio of concentrated sulfuric acid to ore pulp is preferably (20-50) g:1 L, more preferably (25-45) g:1 L, and more preferably (27-35) g:1 L. Specifically, the concentrated sulfuric acid may be 98% concentrated sulfuric acid.

[0058] In the present invention, during the stirring leaching process, the pH value is preferably controlled to be 0.4 to 1.0, more preferably 0.5 to 0.9, and more preferably 0.6 to 0.8.

[0059] In the present invention, the stirring rotation speed of the stirring leaching is preferably 200 to 500 rpm, more preferably 250 to 450 rpm, and more preferably 300 to 400 rpm.

[0060] In the present invention, the residence time of the slurry in the batching device is preferably 20 to 60 min, more preferably 25 to 55 min, more preferably 30 to 50 min, and more preferably 35 to 45 min.

[0061] In the present invention, the stirring speed of the continued stirring leaching is preferably 200 to 500 rpm, more preferably 250 to 450 rpm, and more preferably 300 to 400 rpm.

[0062] In the present invention, the residence time of the slurry in the reaction device is preferably 20 to 60 min, more preferably 25 to 55 min, more preferably 30 to 50 min, and more preferably 35 to 45 min.

[0063] In the present invention, the slag removal and cleaning method preferably includes using a device with a magnetic force to perform magnetic washing and / or elutriation, and more preferably uses a device with a magnetic force to perform magnetic washing or elutriation.

[0064] In the present invention, the mineral processing process preferably further comprises an acid water circulation process.

[0065] In the present invention, the acid water circulation process preferably includes one or more of the following steps: returning the water generated in the weak magnetic separation process to the weak magnetic separation process for recycling;

[0066] The acid leaching liquid obtained after the filter press is returned to the slurry preparation process in the stirring leaching step for recycling;

[0067] The acidic washing water generated during the slag removal and cleaning is neutralized and returned to the slag removal and cleaning process for recycling.

[0068] The invention discloses an engineering application process for high-phosphorus oolitic iron ore roasting to efficiently increase iron and reduce phosphorus. Specifically, a new process of grinding-magnetic separation-demagnetization-stirring leaching dephosphorization-filter pressing and acid reuse-magnetic washing / eluting slag removal is adopted for high-phosphorus oolitic iron ore roasting to achieve the purpose of increasing iron and reducing phosphorus. Stirring leaching adopts a continuous process, which can stabilize the leaching and dephosphorization results. The leaching agent used, sulfuric acid, is equipment-friendly and less corrosive compared with hydrochloric acid, nitric acid, etc.; the newly added demagnetization link in the process can effectively reduce the magnetic agglomeration of magnetically separated iron concentrate, reduce the iron concentrate sedimentation tank bottom during stirring leaching, and eliminate the blockage of the pipeline during slurry transportation; the added quality improvement and slag removal process adopts magnetic washing or elutriation methods to improve the grade of the final product. The new process can make the roasted ore not have to be ground too finely, and the grinding particle size only needs to be less than 325 meshes, accounting for more than 65%. The mineral processing water is returned to the magnetic separation section for use, the acid leaching solution is returned to the stirring leaching section for use, and the cleaning water is returned to the washing section for use after neutralization treatment.

[0069] The present invention is to complete and refine the overall technical solution, better ensure the stability and controllability of the ore dressing process, further improve the effect of iron extraction and phosphorus reduction and the grade of the final product. The above-mentioned high-phosphorus oolitic iron ore roasting ore efficient iron extraction and phosphorus reduction engineering application process can specifically include the following contents:

[0070] An engineering application process for efficiently increasing iron and reducing phosphorus by roasting high-phosphorus oolitic iron ore, using grinding-magnetic separation-demagnetization-agitation leaching-filter pressing-magnetic washing / elution process, can effectively increase the grade of iron ore and reduce the content of key impurity phosphorus, ultimately obtaining high-quality iron concentrate products.

[0071] Specifically, the high-phosphorus oolitic iron ore roasted ore is finely ground to a particle size less than 325 meshes, accounting for 65% to 75%.

[0072] Specifically, the finely ground slurry is separated by a wet weak magnetic separator, and the magnetic field strength is 600Gs to 1500Gs.

[0073] Specifically, the iron concentrate obtained after magnetic separation of the roasted ore is demagnetized after being separated by a wet weak magnetic separator, and the excitation current of the demagnetization process is 2.5 to 3.5A.

[0074] Specifically, the stirring leaching dephosphorization process is continuous stirring leaching, which can stabilize the leaching dephosphorization effect and improve the continuity of the engineering production process:

[0075] (1) Slurry preparation tank: The iron concentrate obtained by magnetic separation and demagnetization is thickened and then slurried with a liquid-to-solid ratio of 2:1 to 8:1, and the slurry is stirred evenly;

[0076] (2) Stirring and leaching batching tank: the uniformly stirred iron concentrate slurry is pumped into the slurry preparation tank, and leached with 20g / L to 50g / L 98% sulfuric acid, the pH value is controlled to vary in the range of 0.4 to 1.0, the magnetically separated iron concentrate is stirred and leached for dephosphorization, the stirring speed is 200rpm to 500rpm, the slurry residence time is 20min to 60min, and no heating is required;

[0077] (3) Stirring leaching reaction tank: The iron ore concentrate slurry stirred evenly in the batching tank enters the main reaction tank through overflow for leaching and dephosphorization. The stirring speed is 200 rpm to 500 rpm, and the slurry residence time is 20 min to 60 min.

[0078] (4) Agitation leaching buffer tank: The iron ore concentrate slurry overflowing from the main reaction tank enters the finished product buffer tank for buffering in preparation for filter pressing.

[0079] Specifically, the deslagging process adopts a wet weak magnetic separator or an electromagnetic elutriator or other equipment with a magnetic separation principle to perform deslagging and separation, so as to separate the iron concentrate from other non-magnetic leaching slag, thereby achieving the purpose of further increasing iron and reducing phosphorus.

[0080] Specifically, the properties of the high-phosphorus oolitic iron ore roasted ore are: total iron grade TFe55.00%~63.00%, P content of 0.50%~1.50%, S 0.02%~0.20%, CaO of 0.50%~2.50%, MgO 0.10%~1.00%, SiO2 content of 4%~8% and Al2O3 content of 4%~8%.

[0081] Furthermore, the present invention provides an engineering application process for efficiently increasing iron and reducing phosphorus by roasting high-phosphorus oolitic iron ore, comprising the following steps:

[0082] (1) Grinding process: The roasted ore obtained by suspended magnetization roasting of high-phosphorus oolitic iron ore is prepared for grinding, and is finely ground to -325 mesh, accounting for 65% to 75%. It is not necessary to grind too finely;

[0083] (2) Magnetic separation process: After grinding, wet weak magnetic separation is carried out to discard part of the tailings. The magnetic field strength does not need to be too high, 600Gs~1500Gs is sufficient;

[0084] (3) Demagnetization process: The overflow concentrate from magnetic separation enters the demagnetization process, and the optimal demagnetization current parameter is 2.5-3.5A to obtain demagnetized magnetic concentrate;

[0085] (4) Stirring leaching process: The demagnetized iron concentrate obtained in step (2) is densely slurried, and the liquid-solid ratio of the stirring leaching is 2:1 to 8:1. The stirring leaching is continuous stirring, and is divided into three parts: slurry preparation, leaching, and buffering. The uniformly stirred iron concentrate slurry is poured into the slurry preparation tank, and leached with 20 to 50 g / L 98% sulfuric acid, and the pH value is controlled to change in the range of 0.4 to 1.0. The magnetically separated iron concentrate is stirred and leached for dephosphorization, the stirring speed is 200 to 500 rpm, and the slurry residence time is 20 min to 60 min. No heating is required; the uniformly stirred iron concentrate slurry from the batching tank enters the main reaction tank through overflow, leaching and dephosphorization, the stirring speed is 200 to 500 rpm, and the slurry residence time is 20 min to 60 min; the iron concentrate slurry overflowing from the main reaction tank enters the finished product buffer tank for buffering in preparation for filter pressing.

[0086] (5) After leaching is completed, a filter press is used to separate the solid and liquid to separate the acid leaching solution from the leached iron ore concentrate.

[0087] (6) Slag removal and cleaning process: Use weak magnetic separation or electromagnetic washing machine and other magnetic equipment to remove slag and clean the leached iron concentrate to further improve the grade of the iron concentrate;

[0088] (7) Acid water circulation process: the water after mineral processing in step (2) is returned to mineral processing for use; the acid leaching solution after leaching is returned to the stirring leaching liquid preparation tank in step (4) so ​​that the acid can be recycled; the washing water generated during slagging is acidic with a pH value between 1 and 6, and is neutralized with lime and returned to step (6) for use.

[0089] See also Figure 1 , Figure 1 The present invention provides a schematic diagram of the process flow of the new process for the combined iron extraction and phosphorus reduction of high-phosphorus oolitic iron ore roasting and smelting. In which, 1 roasting ore; 2 grinding; 3 magnetic separation; 4: demagnetization; 5 concentrate thickening; 6 stirring leaching; 7 filter pressing; 8 magnetic washing slag; 9 iron concentrate product; 10 tailings; 11 acid leaching solution; 12 tailings; 13 adding concentrated sulfuric acid.

[0090] The above content of the present invention provides an engineering application process for efficient iron and phosphorus reduction of high-phosphorus oolitic iron ore roasting ore, adopts a new process of grinding-magnetic separation-demagnetization-stirring leaching dephosphorization-slag removal, and the stirring leaching adopts sulfuric acid leaching dephosphorization to reduce the corrosion of the equipment and reduce the amount of sulfuric acid; the newly added demagnetization link can effectively reduce the magnetic agglomeration of iron concentrate, reduce the iron concentrate sedimentation phenomenon and the blockage of the slurry transportation pipeline during the stirring leaching process; weak magnetic separation washing or electromagnetic washing process can further improve the quality of the final product, achieve the purpose of iron and phosphorus reduction, and the process is particularly suitable for the engineering application production of leaching and dephosphorization of difficult-to-handle high-phosphorus oolitic iron ore roasting ore. The present invention has the characteristics of reasonable process structure, simple and easy operation, low energy consumption, low acid consumption, good iron and phosphorus reduction effect, and environmental friendliness.

[0091] The new combined process for high-phosphorus oolitic iron ore roasting and phosphorus reduction beneficiation provided by the present invention can adapt to the leaching and dephosphorization of roasted ore, which is an artificial magnetite with strong magnetism. The designed grinding-magnetic separation-demagnetization-stirring leaching and dephosphorization-filter pressing-magnetic washing / elution and slag removal process can stabilize dephosphorization, enhance operating efficiency, significantly improve the quality of iron concentrate products, and improve engineering application effects; at the same time, it reduces the grinding fineness, reduces the consumption of leaching agent sulfuric acid, reduces the use of new water, etc., saves costs and increases efficiency, and greatly improves economic and environmental benefits. The present invention solves the engineering application problem of high-phosphorus oolitic iron ore roasting and iron reduction, opens the last barrier for the development and utilization of such ores, and lays the foundation for the large-scale industrial development and utilization of high-phosphorus oolitic iron ore.

[0092] The new combined beneficiation and smelting process provided by the present invention effectively solves the problems that the iron concentrate grinding particle size is too fine, the iron concentrate is easy to be stirred in the sedimentation tank during stirring and leaching, the dephosphorization effect of the product is unstable, and the iron grade of the final product is not high during the engineering application process. The invention is characterized by reducing grinding and low energy consumption; stirring and leaching adopts continuous leaching and stable dephosphorization; the acid leaching liquid is returned for leaching to achieve the purpose of acid recycling, etc., which can reduce the sulfuric acid cost by 30%, the product is stable TFe>64%, P<0.2%, and the content of other silicon and aluminum impurities does not exceed the standard; the used water is also comprehensively utilized, and the whole process is energy-saving, environmentally friendly, and very environmentally friendly.

[0093] The operation results show that the process is particularly suitable for the engineering application production of leaching and dephosphorization of difficult-to-treat high-phosphorus oolitic iron ore roasting. The test ran continuously for 72 hours without interruption. The continuously produced iron concentrate product stably reached a TFe of more than 64%, and the key impurity phosphorus content P<0.2%.

[0094] In order to further illustrate the present invention, a beneficiation process of a high-phosphorus oolitic iron ore roasted ore provided by the present invention is described in detail below in combination with embodiments. However, it should be understood that these embodiments are implemented on the premise of the technical scheme of the present invention, and detailed implementation methods and specific operating procedures are given only to further illustrate the features and advantages of the present invention, rather than to limit the claims of the present invention, and the protection scope of the present invention is not limited to the following embodiments.

[0095] Example 1

[0096] Roasted ore (A#) grinding-magnetic separation-demagnetization-leaching-filter pressing-magnetic washing continuous expansion test

[0097] The comprehensive grade of the A# roasted ore is 60.78% TFe, and contains 0.78% P. Further chemical analysis of the calcium, magnesium, aluminum, silicon and other contents of the comprehensive ore shows that, as shown in Table 1, the CaO content is 1.61%, the MgO content is 0.49%, the SiO2 content is 4.67% and the Al2O3 content is 4.76%. The sulfur content is relatively low, containing 0.027% S. Table 1 shows the multi-element chemical analysis results (%) of the roasted ore A# in Example 1 of the present invention.

[0098] Table 1

[0099] Fe P CaO MgO <![CDATA[SiO2]]> <![CDATA[Al2O3]]> 60.78 0.78 1.61 0.49 4.67 4.76 K S Ti Mn V Zn 0.014 0.027 0.19 0.21 0.079 0.028

[0100] After the expansion test process and equipment related debugging were completed, the A# roasted iron ore grinding-magnetic separation-demagnetization-leaching-magnetic washing continuous expansion test was carried out:

[0101] (1) Grinding process: The roasted ore obtained by suspended magnetization roasting of high-phosphorus oolitic iron ore is ground, and the grinding particle size to -325 mesh accounts for 68.90%, which is better, and it is not necessary to grind too fine;

[0102] (2) Magnetic separation process: After grinding, wet weak magnetic separation is carried out to discard part of the tailings. The magnetic field strength does not need to be too high, 720Gs is sufficient;

[0103] (3) Demagnetization process: The overflow concentrate from magnetic separation enters the demagnetization process, and the optimal demagnetization current parameter is 3.0A to obtain demagnetized magnetic concentrate;

[0104] (4) Stirring leaching process: The demagnetized iron concentrate obtained in step (2) is densely slurried, and the optimal liquid-solid ratio of the stirring leaching is 3:1. The stirring leaching is continuous stirring, and is divided into three parts: slurry preparation, leaching, and buffering. The uniformly stirred iron concentrate slurry is poured into the slurry preparation tank, preferably, leached with 27.6g / L 98% sulfuric acid, and the pH value is controlled to vary in the range of 0.40 to 1.0. The magnetically separated iron concentrate is stirred and leached for dephosphorization, the stirring speed is 300rpm, and the slurry residence time is 25min; the uniformly stirred iron concentrate slurry from the batching tank enters the main reaction tank through overflow, leaching and dephosphorization, the stirring speed is 300rpm, and the slurry residence time is 25min; the iron concentrate slurry overflowing from the main reaction tank enters the finished product buffer tank for buffering in preparation for filter pressing.

[0105] (5) After leaching is completed, a filter press is used to separate the solid and liquid to separate the acid leaching solution from the leached iron ore concentrate.

[0106] (6) Slag removal and cleaning process: Use weak magnetic separation or electromagnetic washing machine and other magnetic equipment to remove slag and clean the leached iron concentrate to further improve the grade of the iron concentrate;

[0107] (7) Acid water circulation process: the water after mineral processing in step (2) is returned to mineral processing for use; the acid leaching solution after leaching is returned to (4) the stirring leaching liquid preparation tank so that the acid is recycled; the washing water generated during slagging is acidic with a pH value between 1 and 6, and is neutralized with lime and returned to (6) for use.

[0108] The process was stably operated for 72 hours, and the test results are shown in Table 2. Table 2 shows the chemical multi-element analysis results of the magnetically washed concentrate of Example 1 of the present invention.

[0109] Table 2

[0110] Element TFe P CaO MgO <![CDATA[Al2O3]]> <![CDATA[SiO2]]> Na content 64.17 0.15 0.10 0.40 4.14 3.99 0.033 Element K S Ti Mn V Zn content 0.0091 0.005 0.18 0.18 0.077 0.027

[0111] A total of 1152 kg of roasted iron ore was processed and 920 kg of iron concentrate was produced, which further verified the grinding-magnetic separation-leaching-filter pressing-magnetic washing process. The final iron concentrate product had a TFe content of 64.17% and a P content of 0.15%, meeting the technical indicators of Fe>64% and P<0.2%.

[0112] The test was run continuously for 72 hours, and the acid consumption for roasting ore was 44.12 kg / ton of ore, which saved one third of sulfuric acid compared with the acid consumption of 66 kg / ton of ore in single leaching.

[0113] The tail liquid after multiple cycles of the acid leaching liquid has its main chemical components as shown in Table 3. The liquid mainly contains 8.30 g / L of Fe, 3.55 g / L of P, and 1.81 g / L of Al. The ion concentration in the acid washing liquid is relatively low, and the water is mainly returned to the washing after neutralization treatment. After the acid liquid is neutralized and precipitated with lime, iron, phosphorus, and aluminum are precipitated, and the precipitation rate reaches more than 99%, the precipitation rate of magnesium reaches 75.77%, and the precipitation rate of silicon reaches 83.79%, which meets the demand for circulating water. Table 3 Analysis of the main chemical components of the tail liquid obtained in Example 1 of the present invention.

[0114] Table 3

[0115] sample Fe g / L P g / L Al g / L Ca g / L Mg g / L Si g / L Acid leaching solution 8.3 3.55 1.81 0.69 0.26 0.29 Acidic cleaning liquid 0.15 0.14 0.086 0.50 0.018 0.031

[0116] Example 2

[0117] Roasted ore (B#) grinding-magnetic separation-demagnetization-leaching-filter pressing-magnetic washing continuous expansion test

[0118] The test process and conditions are the same as those in Example 1, except that the grade of the roasted ore is different. The chemical multi-element analysis results of the B# roasted ore are shown in Table 4, which contain 60.24% Fe, 0.74% P, 1.16% CaO, 0.28% MgO, 4.83% SiO2 and 5.06% Al2O3, and the sulfur content is 0.037% S. Table 4 shows the multi-element chemical analysis results (%) of the roasted ore B# in Example 2 of the present invention.

[0119] Table 4

[0120] Fe P CaO MgO <![CDATA[SiO2]]> <![CDATA[Al2O3]]> 60.24 0.74 1.16 0.28 4.83 5.06 K S Ti Mn V Zn 0.011 0.037 0.19 0.19 0.082 0.027

[0121] For the roasted ore B# sample, 350 kg of iron concentrate was continuously produced. The iron concentrate product contained 64.36% TFe and 0.15% P, reaching the technical indicators of TFe>64% and P<0.20%, as shown in Table 5. The amounts of other major impurity elements were: CaO 0.07%, MgO 0.37%, SiO2 3.97%, and Al2O3 4.12%. Table 5 is the chemical multi-element analysis (%) of the main components of the B# iron concentrate product in Example 2 of the present invention.

[0122] Table 5

[0123] TFe P CaO MgO <![CDATA[SiO2]]> <![CDATA[Al2O3]]> 64.36 0.15 0.07 0.37 3.97 4.12

[0124] The new combined process for high-phosphorus oolitic iron ore roasting and phosphorus reduction beneficiation provided by the present invention can adapt to the leaching and dephosphorization of roasted ore, which is an artificial magnetite with strong magnetism. The designed grinding-magnetic separation-demagnetization-stirring leaching and dephosphorization-filter pressing-magnetic washing / elution and slag removal process can stably dephosphorize, enhance operating efficiency, significantly improve the quality of iron concentrate products, and improve engineering application effects; at the same time, it can reduce the grinding degree, reduce the consumption of leaching agent sulfuric acid, reduce the use of new water, etc., save costs and increase efficiency, greatly improve the economic benefits and environmental benefits, and lay a foundation for the large-scale industrial development of high-scale oolitic iron ore.

[0125] The above is a detailed introduction to the engineering application process of high-phosphorus oolitic iron ore roasting ore for efficient iron and phosphorus reduction provided by the present invention. The principles and implementation methods of the present invention are described in detail in this article using specific examples. The description of the above embodiments is only used to help understand the method and core ideas of the present invention, including the best mode, and also enables any technician in the field to practice the present invention, including the manufacture and use of any device or system, and the implementation of any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in several ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements that are not different from the literal expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A beneficiation process for roasted high-phosphorus oolitic iron ore, characterized in that: The following steps are involved: 1) grinding the roasted ore after roasting the high-phosphorus oolitic iron ore to obtain ground ore; 2) subjecting the ground ore obtained in the above step to weak magnetic separation and then demagnetization to obtain demagnetized ore; 3) The demagnetized ore obtained in the above steps is subjected to stirring leaching and filter pressing to obtain leached ore, and then slag removal and washing to obtain iron ore concentrate.

2. The ore dressing process according to claim 1, characterized in that: The roasted ore comprises, by element mass content, 55.00% to 63.00% TFe, 0.50% to 1.50% P, 0.02% to 0.20% S, 0.50% to 2.50% CaO, 0.10% to 1.00% MgO, 4% to 8% SiO2 and 4% to 8% Al2O3.

3. The ore dressing process according to claim 1, characterized in that: The roasting method includes suspended magnetization roasting; The particle size of the ore grinding is less than 325 mesh, and the mass of the particles accounts for 65% to 75%.

4. The ore dressing process according to claim 1, characterized in that: The weak magnetic separation is specifically wet weak magnetic separation; The magnetic field strength of the weak magnetic separation is 600-1500 Gs.

5. The ore dressing process according to claim 1, characterized in that: The demagnetization excitation current is 2.5 to 3.5A; The stirring leaching method is continuous stirring leaching, including slurry preparation, leaching and buffering steps.

6. The ore dressing process according to claim 1, characterized in that: The stirring leaching process comprises the following steps: The demagnetized ore slurry after slurry adjustment is sent to the slurry preparation device, and concentrated sulfuric acid is added for stirring and leaching, and then overflows to the leaching reaction device for further stirring and leaching, and then overflows to the buffer device.

7. The ore dressing process according to claim 1, characterized in that: The liquid-to-solid ratio of the slurry after slurry adjustment is (2-8):1; The ratio of the concentrated sulfuric acid to the ore pulp is (20-50) g:1L.

8. The ore dressing process according to claim 1, characterized in that: During the stirring leaching process, the pH value is controlled to be 0.4 to 1.0; The stirring speed of the stirring leaching is 200 to 500 rpm; The residence time of the slurry in the batching device is 20 to 60 minutes.

9. The ore dressing process according to claim 1, characterized in that: The stirring speed of the continuous stirring and leaching is 200 to 500 rpm; The residence time of the slurry in the reaction device is 20 to 60 minutes; The slag removal and cleaning method includes using a device with magnetic force to perform magnetic washing and / or elutriation.

10. The ore dressing process according to claim 1, characterized in that: The mineral processing technology also includes an acid water circulation process; The acid water circulation process comprises one or more of the following steps: returning the water generated in the weak magnetic separation process to the weak magnetic separation process for recycling; The acid leaching liquid obtained after the filter press is returned to the slurry preparation process in the stirring leaching step for recycling; The acidic washing water generated during the slag removal and cleaning is neutralized and returned to the slag removal and cleaning process for recycling.

Images